Field of the Invention
The invention is related to an electronic apparatus, and particularly to an electronic apparatus with power over coaxial cable function.
Description of Related Art
In a power over coax (PoC) system, a master device can supply power via a power circuit and a low-pass circuit disposed therein as well as provide communication data via a transceiving circuit and a high-pass circuit disposed therein. The master device can load the communication data onto the power and transmit the same to a remote device via a coaxial cable. The remote device can perform low-pass filtering operation on a signal from the coaxial cable via the low-pass circuit disposed therein to obtain the power, and performs high-pass filtering operation on the signal from the coaxial cable via the high-pass circuit disposed therein to obtain the communication data. In this manner, the master device can achieve the objective of supplying power to and communicating with the remote device via the coaxial cable.
Generally speaking, it is required for the low-pass circuit of the master device and the low-pass circuit of the remote device to adopt a serial combination of a plurality of particular RLC circuits so as for them to match one another and prevent affecting the impedance characteristic of a data communication frequency band (high frequency band), thereby avoiding that a noise of the power is transmitted to the coaxial cable via the low-pass circuit and then affects the signal quality of the communication data. Once the signal quality of the communication data is affected, the communication between the master device and the remote device may fail. Accordingly, the matching of the low-pass circuit of the master device and the low-pass circuit of the remote device is highly important and plays a decisive role for the quality of the master device and remote device.
However, in the master device and the remote device, the plurality of particular RLC circuits adopted in the low-pass circuit makes the circuit design to become complex. In addition, when the remote device is to be designed for miniaturization, there is signal interference generated between elements in the plurality of RLC circuits due to close arrangement of the elements, making it difficult to design the circuit. In particular, if the remote device adopts a switching power converter to process power, then the noise generated during switching operation of the switching power converter is still likely to be feedback to the coaxial cable via the RLC circuits and interfere the communication data.